The present invention relates generally to seals, and more particularly to a finger seal with metering ports.
There are a variety of gas turbine engine configurations, including two-spool, high-bypass engines. Such an engine typically includes a high pressure spool, a combustion system and a low pressure spool disposed within an engine case to form a generally axial, serial flow path about the engine centerline. The high pressure spool includes a high pressure turbine, a high pressure shaft extending axially forward from the high pressure turbine, and a high pressure compressor connected to a forward end of the high pressure shaft. The low pressure spool includes a low pressure turbine, which is disposed downstream of the high pressure turbine, a low pressure shaft, which typically extends coaxially through the high pressure shaft, and a low pressure compressor connected to a forward end of the low pressure shaft, forward of the high pressure compressor. A fan is also connected to the low pressure spool, forward of the low pressure compressor. The combustion system is disposed between the high pressure compressor and the high pressure turbine and receives compressed air from the compressors and fuel provided by a fuel injection system. A combustion process is carried out within the combustion system to produce high energy exhaust gases to produce thrust and turn the high and low pressure turbines, which drive their respective compressors and the fan to sustain the combustion process.
The high energy gases contain a substantial amount of thermal energy, which is transferred to the high and low pressure turbines. Therefore, certain components of the high and low pressure turbines are cooled and/or pressurized using relatively cool air that is bled from the low pressure compressor, the high pressure compressor, and/or the fan bypass duct. This cooling air needs to be allowed to flow through and/or around different structures in the gas turbine engine to arrive at the targeted areas. Because the gas turbine engine has already performed some work on the cooling air, it is important to use the air wisely or else the efficiency of the engine will decrease.